Preheat your oven according to the cake mix package instructions.
In a mixing bowl, combine the yellow cake mix, ½ cup of melted butter, and 1 large egg. Mix until well blended.
Spread the cake mixture evenly in a greased baking dish.
In another bowl, beat together the softened cream cheese, 2 large eggs, the remaining ½ cup of melted butter, powdered sugar, and vanilla extract until smooth.
Pour the cream cheese mixture over the cake layer in the baking dish.
Sprinkle the toffee bits and chopped pecans (if using) on top of the cream cheese layer.
Drizzle the caramel sauce over the top.
Bake in the preheated oven until the cake is set and golden, following the time suggested on the cake mix box.
Once baked, allow the cake to cool slightly before serving. Drizzle with additional caramel sauce if desired.
